This application is not referenced in any microfiche appendix.
1. Field of the Invention
The present invention relates generally to vacuum cast ceramic fiber insulators, specifically those having the ability to raise, lower or maintain temperature by utilizing heating and/or cooling controls in a low temperature apparatus.
2. Prior Art
The use of injection/extrusion machines to create plastic parts is well known. Plastic compounds are subjected to heat in order to render it into a fluid state. After it reaches a fluid state, the compound is then forced under pressure into mold cavities or through dies. It is well known in the art that the fluid resin compounds are directed into the mold cavities or dies by way of injection or extrusion barrels. In order to insure the optimum flow characteristics of the compound, the barrels are equipped with heating mechanisms in order to control the temperature of the compound. Multiple types of heating bands have been disclosed in the prior art. The most common is the heating coil that surrounds the barrel and conducts heat to the compound as it flows through the barrel.
The optimization of the flow characteristics of the fluid compound is dependent upon the ability to control the amount of heat applied to the barrel as the fluid compound passes through it. Therefore, an improved heating and cooling mechanism is needed to improve the efficiency in the attempt to achieve the optimal flow characteristics for the fluid compound.
The present invention is directed to a ceramic insulating and heating/cooling band. The prior art does not demonstrate the use of such bands with low temperature apparatus, in the range of less than 1000xc2x0 C./1600xc2x0 F. Thus, there is a need for a temperature control mechanism for use in low temperature apparatus, such as injection/extrusion machines.
The present invention is generally directed toward a device for effectively insulating while heating and/or cooling a fluid plastic compound more efficiently. Specifically, the present invention is directed toward a device having the ability to maximize the controllability of the temperature of a fluid plastic compound in connection with the injection/extrusion process of low temperature apparatus, such injection molding and extrusion machines
A discussion concerning specific terms used herein is in order. The term xe2x80x9cceramic bandxe2x80x9d is synonymously referred to as a vacuum cast ceramic fiber heater band, machinable ceramic fiber board or other materials of the ceramic genre. While extrusion machines can be different from injection molding machines, the present invention can be utilized in connection with both types of machines. Therefore, reference to one type of machine should be viewed as reference to both types of machines. The use of the terms xe2x80x9clow temperaturexe2x80x9d and xe2x80x9clow temperature apparatusxe2x80x9d herein refers to those apparatus which cannot obtain temperatures of 1000xc2x0 C./1600xc2x0 F. and higher.
The present invention utilizes a ceramic band which surrounds the barrel of the injection/extrusion machine. The ceramic band acts as an insulator for the heat contained on and within the barrel. Further, the ceramic band incorporates heating elements and cooling mechanisms to provide the ability to accurately and quickly change the temperature of the barrel.
The heating/cooling mechanisms can be, but not necessarily, cast within the ceramic band providing an efficient temperature control unit.
The ceramic band can take a plurality of different forms, including but not limited to a half-section configuration or individual block configuration. In any configuration, the band fits around the exterior portion of the barrel and provides a heating and/or cooling effect to such barrel, thereby heating or cooling the fluid plastic compound flowing through such barrel.
With respect to the heating mechanisms, standard heating elements are cast within the ceramic band. With respect to the cooling mechanisms, air or fluid can be utilized to decrease the temperature of the barrel. Suitable apparatus for providing air or fluid cooling ability is provided through a manifold apparatus either in the interior or on the exterior of the ceramic band.
In addition, monitoring devices such as LED lights, can be utilized to monitor the present invention and advise the operator its current operational condition.
The primary objective of the present invention is to provide a self-insulated heating and cooling unit used in connection with low temperature plastics injection/extrusion machines.
Another object of the present invention is to provide a device which insulates and provides improved temperature controllability for the barrel portion of injection and extrusion machines.
Another object of the present invention is to provide a faster responding device utilizing insulation, heating elements and air and/or water cooling devices to alter the controlled temperature of the barrel portion of injection and extrusion machines.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals.